Well if you don't understand the data sheet, you really aren't going to get far.
Don't try to read and understand the data sheet all in one go. What you need to do is to start with something simple, such as turning an output on and off. For that you only need a tiny fraction of the data sheet. Then progress to using the i2c port (I think) to read from the SD card, or outputting a PWM waveform.
If you don't know how to turn an output on and off, you read Nigel's tutorials and allow a couple of months full time.